1. Field of the Invention
The present invention relates to the field of sampling, feeding or inoculating of material from or to a vessel or conduit.
2. Description of Related Art
Quality products require precise control of many phases of a production process. It is also true that it is necessary to maintain the integrity of the process and to protect the surroundings from the process. While many advances have been made in the development of sensors for measuring the condition of a specific process on-line which will aid in maintaining this process integrity, many of the characteristics of processes still need to be measured off-line through the physical and/or chemical analysis of an actual sample of the process. The removal of the sample from the process has to be conducted in a way that will preserve the integrity of the process, the surrounding environment as well as the integrity and character of the sample itself.
In a related but different procedure, many processes require inoculation of seed organisms or catalysts into a process to initiate the conversion of a set of substrate materials into other process intermediates or a final product or set of products. Sometimes this seed material is a live organism, a component of a live organism or another form of catalyst. In any case, these materials frequently need to be added to a process in a way that maintains the integrity of the process, the materials being added and their source, the integrity of the surrounding environment, or, perhaps, all of these.
There are examples of devices in the prior art that provide a means to deliver or withdraw materials from a process while maintaining the integrity of the process, the sample or the feed material or the surrounding environment but these devices are restricted in their effectiveness, particularly in their abilities to maintain the integrity or character of either the sampled material or material being added to the process because these devices have designs that are optimized for use in certain physical orientations. When used in orientations other than those they are designed for, these devices frequently suffer from the presence of crevices, particularly between component joints exposed to the process, and from design features that inhibit free flow and drainage of flowable materials through the device, resulting in pooling within the device. Both the crevices and pooling phenomena result in material carryover from one sampling, feeding or inoculation episode to the next, causing the deterioration in quality of any subsequent material introduced through sampling, feeding or inoculating into these devices.
It is also the case that some of these devices are not designed to be reused or, if they are designed for reuse, must be removed from the process and cleaned and sometimes resterilized before being able to be used again with the process.
There is a need for an apparatus that can be fitted, either permanently or removably, into a process which will allow materials to be fed, inoculated to or sampled from a process through a device principally designed to provide access to the process from above but which may provide reasonably good access to a process when installed at angles from vertical to horizontal. It is also desirable that an embodiment of this device provide a means by which it can be washed and sterilized in place and a means by which the thermal and electrical conditions inside the device be generally insulated from those of the process into which it is inserted. It is further desirable that the device, when placed in installations from vertical to horizontal relative to the process, be able to accumulate flowable materials occurring in the device in an area where they may be expelled or washed out by the introduction of other flowable materials under pressure coming either from the process or a second source through another access into the device.
In the existing art, there are examples of devices that provide a means for adding materials to the process but do not provide a means for washing and resterilizing in place and for effectively draining sampled material or cleansing, rinsing or sterilizing solutions from within the device.
Accordingly, it is an object of the present invention to provide a device which allows for the feeding or inoculating of a material into a process, and which can be easily washed and resterilized in place.
It is another object of the present invention to provide a device which can be used in an orientation from the vertical to the horizontal and which can still effectively drain sampled material or cleansing, rinsing or sterilizing solutions from within the device.
It is a further object of the present invention to provide a device which enhances the free flow of material through the device in order to prevent the pooling of the material within the device. This prevents the contamination of the sampled material, material added to the process, or the process itself.
It is yet another object of the present invention to provide a device which can be reused over and over again, and which can be cleaned or sterilized without having to remove the device from the process.
The valve of the present invention is designed primarily to take samples from a vertical installation although it can be used effectively at angles of installation down to horizontal. The valve works by providing a collection basin or well at a lower portion of the collection chamber of the valve body of the dip tube valve assembly. A drain passage opening is provided adjacent to the opening of the orifice where the orifice opens into the collection chamber in the valve body. By arranging the opening to the drain passage even with or lower than the inside margin of the orifice opening, a flowable material inside the valve body, including the collection chamber, the inlet or drain passages, will drain down into the opening of the drain passage. When this valve is installed at a positive angle from the horizontal, up to and including the vertical, sample material will not passively drain out of it.
Material may be sampled through the valve by supplying overpressure to force material inside the vessel or conduit through the orifice and up and out through the drain passage. However, once the orifice is closed, this material will flow back down into the collection chamber of the valve. In order to fully remove sampled material from within the valve a flowable material must be fed through the inlet passage into the collection chamber after the sampling orifice has been resealed. The introduction of this material will displace or flush the sampled material collected in the bottom of the collection chamber, forcing the sampled material up and out of valve through the drain passage.
The collection basin or well formed at the bottom of the collection chamber enhances the removal of the sampled material, since the material remaining in the collection chamber flows into the collection basin or well to adjacent the opening of the drain passage. Therefore, when the flowable material is provided through the inlet, the sampled material which has collected at the opening of the drain passage can be easily removed.
In a first embodiment of the present invention, the axis of the inlet can be oriented non-parallel to a plane passing through the major diameter of an embodiment with a round internal collection chamber. This off-center introduction of the flowable material will create a vortex flow through the collection chamber, scouring the surfaces of the chamber and forcing any flowable material therein down to the opening in the drain passage and then up and out through the drain passage.
In a second embodiment of the present invention, the opening of the drain passage can be oriented in a similar but opposing fashion so as to open into the vortexing flow. The effect of this is to sweep material down, into and then up and out of the drain passage.
While the valve of the present invention is similar in many aspects to sample valve embodiments previously disclosed, one of which is the dependence on gravity to direct the flow of material down through the collection chamber and then down into the drain passage opening, the valve of the present invention differs in that previous designs were only capable of supplying the sampled material out of the valve through the drain passage to a sample vial simply by means of gravity flow. The dip tube valve assembly of the present invention; however, includes an active scouring motion provided by a second flowable material supplied through the inlet passage to generally remove and deliver all of the sampled material up through and out of the drain passage to a sample vial.
It should be noted that the device of the present invention can be used for sampling a material without an inlet passage. This can be accomplished through the use of over-pressure of the source of sampled material alone or through the use of over-pressured sample material followed by a second flowable material through the sampling orifice. While in the second instance, all of the sampled material might be removed up through the drain passage to a sample vial, in the first instance, once the sampling orifice is resealed, sampled materials in the interstices of the valve remain in the valve until either the next sampling episode or until other active methods are used to remove them.
The above objects have been accomplished by the dip tube valve assembly of the present invention. An apparatus for sampling or feeding a flowable material through a wall of a vessel or conduit includes a body; a collection chamber formed in said body; a drain passage, said drain passage having an opening operatively connected to said collection chamber; an orifice formed in said body and in communication with said collection chamber, said orifice being located generally adjacent the opening of the drain passage; and a sealing device for sealing and unsealing said orifice.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.